Soy bean flour



Patented May 7, 1935.

UNITED STATES 2,000,317 SOY BEAN FLOUR William B.

Bishop, Decatur, Ill., Staley Manufacturing Company,

assirnor to A. E. Decat I a corporation of Delaware No Drawing. Application March 2, 1933,

Serial No.

3 Claims.

This invention relates to the production of an edible soy bean flour and has for its object the production of an improved soy bean flour of low oil and high protein content. Prior to the instant invention soy bean fiours generally upon the market have contained from 20% to 25% of oil or fat. The presence of such a large percentage of oil or fat reduces materially the percentage of protein so that the flour contains less body building constituents. Furthermore, the oil or fat thus contained in soy bean flour has a tendency to become rancid after a period of from one to three months.

Prior to this invention commercial processes employed for the extraction of the oil have either been too expensive or have produced a cake from which edible fiour could not be produced satisfactorily. Processes have been known, in which organic solvents, such as gasoline, benzene, or carbon tetrachloride have been used to extract the oil. Such processes have been expensive and have only been usable in batch operations. More- ,over, processes employing organic solvents have removed both the coloring matter and other valuable ccnstituents, such as lecithin, and have left the fiour light in color and lacking in the nutty flavor so desirable in soy bean fiour.

Where the oil has been extracted in expellers, it has heretofore been customary to heat the cake to a high temperature in the extraction of the oil, with the result that the resulting flour was brown in color, was possessed of a burned taste, and the proteins contained have been 'considerably altered by denaturing due to the heating.

This invention has for its principal object the provision of a soy bean fiour of low oil content, from which objectionable tastes and odors have been removed, but which otherwise has all the physical and chemical characteristics of a flour made from the whole beans.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description.

The process embodying my present invention is as follows: The whole beans are first cleaned and dehulled. They may then be treated to remove objectionable tastes and odors, preferably by the process described and claimed in copending application, Serial No. 639,044, filed October 22, 1932, for improvement in the treatment of soy beans, and assigned to A. E. Staley Manufacturing Company, a corporation of the .State of Illinois, assignee of this application.

In accordance with this process the moisture content of the beans is materially increased and the beans are subjected for a short period of time to a high temperature, then first sharply reducing the temperature. Later, final cooling and drying are accomplished. The beans are dried preferably to an extent leaving 4% to 6% of moisture in the beans. Thereafter the beans are ground to approximately 10-20 mesh, to a temperature of approximately 200 to 220 F., and passed through an expeller to extract the oil content down to 7% or 8% or lower. Care is taken to maintain the ground beans at relatively low temperatures during the expelling to prevent scorching or browning which materially alters the color and taste of flour made from the final cake. A low temperature is maintained by cooling parts of the expeller itself .by water at to F., and by passing the beans through the expeller at highspeed and at sufiiciently low pressure to prevent browning of the resultant cake. Thereafter, the cake is quickly cooled. This is accomplished by breaking up the cake and spreading it out for large direct contact with the cake has the rich yellow color of flour from the whole bean and the taste of the bean, except for the objectionable tastes and odors earlier removed, is preserved. The protein content is materially higher than the protein content of the flours now usually made and which contain from 20% to 25% of oil.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the steps and their order of accomplishment of the process described without departing from the spirit and scope 0 material advantages, the process hereinbefore described being merely a preferred embodiment thereof.

I claim: I

l. The process for preparing soy bean flour, which comprises increasing the normal moisture content of soy beans, subjecting the moist beans to a relatively high temperature for a short period of time, drying said beans at a reduced temperature, expelling oil from the dried beans at a relatively low temperature, and grinding the expelled beans into flour form.

2. The process of treating soy beans to produce fiour therefrom, which comprises treating soy beans to remove undesirable flavor and odor therefrom, subjecting the beans to an expelling step under sufficient pressure to press out sub- 6 expelling step, and :rindin: the expelled beam has been materially aflected. subjecting the beam into flour form. to an expelling step at a temperature aumciently I 3. The process for producing flour from soy low that the color of the beans will not be matebeane, which ompriaeg increasing the moisture rially increased, and zrindinz the beam into content or the beam without extracting the natuflour i'orm. ral color therefrom, subjecting the beam to a l WILLIAM B. BIBHOP. 4 relatively high tempera ure for a short period to p .7 

